JP6735669B2 - Polyurethane with reduced aldehyde emissions - Google Patents

Description

The present invention relates to the production of polyurethanes, wherein (a) polyisocyanate, (b) polymer compound having a group reactive with isocyanate, (c) catalyst, (d) general formula R ¹ —CH ₂ —. R ² (in the formula, R ¹ and R ² are independently of each other, a compound represented by the general formula —C(O)—R ³ (wherein R ³ is —NH ₂ , —NH—R ⁴ , —NR ⁵ R). ⁶ , OR ⁷ or R ⁸ (wherein R ⁴ , R ⁵ , R ⁶ , R ⁷ or R ⁸ independently represents an optionally substituted aliphatic, araliphatic or aromatic hydrocarbon) CH-acidic compound) selected from the group consisting of) selected from the group consisting of) or an electron withdrawing moiety of —CN), and optionally (e) a blowing agent, (f) a chain extender and The/or crosslinker, and (g) auxiliaries and/or additives are mixed to provide a reaction mixture, which completes the reaction to provide the polyurethane. Furthermore, the invention relates to the polyurethanes produced by this method, and to the use of these polyurethanes inside vehicles.

Polyurethanes are versatile, for example as a binder for seat cushions and party boards in the furniture industry, as insulation in the construction industry, for example as insulation for pipes, hot water tanks and refrigerators, and in the automobile manufacturing industry for example. Used as a coated part. In particular, polyurethanes are used in the automobile manufacturing industry, for example as spoilers, roof elements and springing elements in automotive exterior materials, and in automotive interior materials roof coverings, carpet backing foams, door coverings, steering rings, operating knobs. And often used as a seat cushion.

In this regard, it is known that polyurethanes tend to emit an unpleasant odor or organic matter which, in high concentrations, leads to health-related problems. Here, for example, the enclosed space inside a building or inside a vehicle such as a car is particularly affected. An example of these emissions is aldehyde emissions. Various attempts have been made to reduce these aldehyde emissions.

For example, EP 1288847 discloses that aldehyde excretion is reduced by the subsequent addition of polymeric substances having primary and/or secondary amino groups. The cause of the reduced emissions is the amine groups in the polymer. Polymeric active ingredients should be provided in already prepared foams, as they are isocyanate-reactive and are largely deactivated by reaction with isocyanates. Here, the drawback is a complicated process with the further step of post-treatment of the foam. It cannot be used in compression systems or closed cell foams.

US 2006/0141236 discloses the use of hydrazine compounds as aldehyde scavengers in polyurethanes. In this case, the active substance is directly incorporated into the polyol component. However, hydrazine and hydrazine derivatives have catalytic activity and can influence the polyurethane reaction. Moreover, only low levels of reduction in aldehyde emissions (about 60%) are obtained.

US 20130203880 discloses the use of polyhydrazodicarbonamide as a reducing substance for aldehyde emissions in polyurethane foams. However, a significant reduction is realized only when the amount of polyhydrazodicarbonamide added is relatively large, 2% to 5.5% by weight of the polyol component. Similarly, since polyhydrazodicarbonamide has catalytic properties, the reaction profile is modified by the addition of this material in this important order.

EP 1428847 US 2006/0141236 US 20130203880

It is an object of the present invention to provide polyurethanes, in particular polyurethane foams, which exhibit a reduction of organic compound emissions, more particularly of aldehyde emissions. A particular purpose is to show a sustained activity against the substances responsible for reducing aldehyde emissions and to not cause further emissions in the polyurethane parts. Furthermore, low-emission polyurethanes should be produced by a simple process in which the substance responsible for reducing the aldehyde emission is added to the reaction mixture for polyurethane production. The aim here is, in particular, to use substances which are cheap and easy to process and which do not impair the production of polyurethanes.

Surprisingly, the object of the present invention was achieved by the method for producing polyurethane. Here, in order to provide a reaction mixture, (a) polyisocyanate, (b) polymer compound having a group reactive to isocyanate, (c) catalyst, (d) general formula R ¹ —CH ₂ — R ² (in the formula, R ¹ and R ² are independently of each other, a compound represented by the general formula —C(O)—R ³ (wherein R ³ is —NH ₂ , —NH—R ⁴ , —NR ⁵ R). ⁶ , OR ⁷ or R ⁸ (wherein R ⁴ , R ⁵ , R ⁶ , R ⁷ or R ⁸ independently represents an optionally substituted aliphatic, araliphatic or aromatic hydrocarbon) CH-acidic compound) selected from the group consisting of) selected from the group consisting of) or an electron withdrawing moiety of —CN), and optionally (e) a blowing agent, (f) a chain extender and The/or crosslinker, and (g) auxiliaries and/or additives are mixed to provide a reaction mixture that completes the reaction to provide the polyurethane.

According to the invention, the term polyurethane comprises all known polyisocyanate polyaddition products. These include isocyanate and alcohol adducts, and also modified polyurethanes, which may include isocyanurate, allophanate, urea, carbodiimide, uretonimine, biuret and other isocyanate adducts. In particular, these inventive polyurethanes are suitable for the production of compressed polyisocyanate polyaddition products such as thermosetting resins, polyisocyanate polyaddition product-based foams such as flexible foams, semi-rigid foams, rigid foams and monoliths. Includes foams, polyurethane coatings and binders. Furthermore, according to the invention, the term polyurethane includes polymer blends comprising polyurethane and other polymers, as well as foams comprising said polymer blends. Preferably, the polyurethane of the present invention is a polyurethane foam or a compressed polyurethane containing no polymer other than the following polyurethane units (a) to (g).

For the purposes of the present invention, the term polyurethane foam uses foam according to DIN 7726. Here, the compressive stress value or compressive strength for compressing the flexible polyurethane foam of the present invention by 10% according to DIN 53 421/DIN EN ISO 604 is 15 kPa or less, preferably 1 kPa to 14 kPa, and particularly 4 kPa to 14 kPa. The compressive stress values for compressing the semi-rigid polyurethane foams of the invention by 10% according to DIN 53 421/DIN EN ISO 604 are from above 15 kPa to below 80 kPa. According to DIN ISO 4590, the open-cell factor of the inventive semi-rigid polyurethane foams and flexible polyurethane foams is preferably greater than 85%, particularly preferably greater than 90%. Further details regarding the flexible polyurethane foams and semi-rigid polyurethane foams of the present invention can be found in "Kunststoffhandbuch [Plastic Handbook], Volume 7, Polyurethane[Polyurethane]", Carl Hanser Verlag, 3rd Edition, 1993, Chapter 5. Found.

The compressive stress value for compressing the rigid polyurethane foam of the present invention by 10% is 80 kPa or more, preferably 120 kPa or more, and particularly preferably 150 or more. Moreover, according to DIN ISO 4590, the closed-cell factor of the rigid polyurethane foams according to the invention is more than 80%, preferably more than 90%. Further details regarding the rigid polyurethane foams of the present invention can be found in "Kunststoffhandbuch [Plastic Handbook], Volume 7, Polyurethane [Polyurethane]", Carl Hanser Verlag, 3rd Edition, 1993, Chapter 6.

For the purposes of the present invention, according to DIN 7726, the term elastomeric polyurethane foam refers to a residual deformation of more than 2% of their original thickness after 10 minutes of short-term deformation of the thickness to 50% according to DIN 53 577. Refers to polyurethane foam not shown. It can also be applied to rigid polyurethane foam, semi-rigid polyurethane foam or flexible polyurethane foam.

Solid polyurethane foams are polyurethane foams according to DIN 7726 which have a marginal zone with a higher density than the core as a result of the molding process. Here, preferably, the overall average apparent density across the core zone and the marginal zone exceeds 100 g/L. Also, the integral polyurethane foam for the present invention can be a rigid polyurethane foam, a semi-rigid polyurethane foam or a flexible polyurethane foam. Other details regarding the integral polyurethane foams of the present invention can be found in "Kunststoffhandbuch [Plastic Handbook], Volume 7, Polyurethane [Polyurethane]", Carl Hanser Verlag, 3rd Edition, 1993, Chapter 7.

Here, in the polyurethane of the present invention, (a) a polyisocyanate, (b) a polymer compound having a group reactive with isocyanate, optionally (c) catalyst, (d) CH-acidic compound, and It is obtained by completing the reaction by optionally mixing with (e) a blowing agent, (f) a chain extender and/or a cross-linking agent, and (g) an auxiliary agent and/or an additive to provide a reaction mixture.

In a preferred embodiment, the polyurethane of the present invention is a polyurethane foam having an average density of 20 g/L to 850 g/L, preferably a semi-rigid polyurethane foam, a flexible polyurethane foam or a rigid polyurethane foam, particularly preferably an elastomer. It is a polyurethane foam, a semi-rigid polyurethane foam, or an integral polyurethane foam of an elastomer. Preferably, the average apparent density of the elastomeric integral polyurethane foam across the core zone and the marginal zone is from 150 g/L to 500 g/L. Preferably, the flexible polyurethane foam has an average density of 10 g/L to 100 g/L. Preferably, the average density of the semi-rigid polyurethane foam is 70 g/L to 150 g/L.

In another preferred embodiment, the polyurethane is a compressed polyurethane having a density of 850 g/L or more, preferably 900 g/L to 1400 g/L, particularly preferably 1000 g/L to 1300 g/L. Here, the compressed polyurethane is obtained without adding a foaming agent. Here, the small amount of blowing agent (eg water) contained in the polyol as a product of the manufacturing process is not considered as a blowing agent. Preferably, the reaction mixture for the production of the compressed polyurethane contains less than 0.2% by weight, preferably less than 0.1% by weight and especially less than 0.05% by weight of water.

Here, preferably the polyurethanes of the invention are used in vehicles, for example ships, aircraft, trucks, cars or buses, preferably cars or buses, in particular cars. Hereinafter, the term automobile interior is used inside a car or bus. Here, the flexible polyurethane foam serves as a seat cushion, the semi-rigid polyurethane foam serves as a side door element or the foam backing of the instrument panel, and the integral polyurethane foam serves as a steering wheel and a control knob. Alternatively, it is possible to use compressed polyurethane as a headrest, for example as a cable-sheathing.

The polyisocyanate component (a) used in the production of the polyurethane of the present invention comprises any polyisocyanate known in the production of polyurethane. These include the aliphatic, cycloaliphatic and aromatic di- or polyvalent isocyanates known from the prior art, and any mixtures thereof. Examples include diphenylmethane 2,2'-, 2,4'- and 4,4'-diisocyanate, a mixture of monomeric diphenylmethane diisocyanate and a large amount of diphenylmethane diisocyanate homologue having a cyclic structure (polymer MDI), isophorone diisocyanate. (IPDI) and its oligomers, tolylene 2,4- and 2,6-diisocyanate (TDI) and mixtures thereof, tetramethylene diisocyanate and its oligomers, hexamethylene diisocyanate (HDI) and its oligomers, naphthylene diisocyanate (NDI), And mixtures thereof.

Preferably, tolylene 2,4- and/or 2,6-diisocyanate (TDI) or a mixture thereof, monomeric diphenylmethane diisocyanate, and/or diphenylmethane diisocyanate homolog having a large amount of cyclic structure (polymer MDI), and The use of a mixture of them. Other possible isocyanates are described, for example, in “Kunststoffhandbuch [Plastic Handbook], Volume 7, Polyurethane” [Polyurethane], Carl Hanser Verlag, 3rd Edition, 1993, Chapters 3.2 and 3.3.2. Described.

The polyisocyanate component (a) is used in the form of a polyisocyanate prepolymer. These polyisocyanate prepolymers are polymer compounds having an excess amount of the above polyisocyanate (component (a-1)), for example, at a temperature of 30 to 100° C., preferably 80° C. and having a group reactive with isocyanate. It is obtained by reacting with (component (a-2)) and/or a chain extender (component (a-3)) to provide an isocyanate prepolymer.

The polymer compound (a-2) and the chain extender (a-3) having a group reactive with isocyanate are known to those skilled in the art, and for example, "Kunststoffhandbuch [Plastic Handbook], Volume 7, Polyurethane[ Polyurethane]”, Carl Hanser Verlag, 3rd Edition, 1993, Chapter 3.1: For example, the following polymer compound (b) having a group reactive to isocyanate is added to isocyanate. It is also possible to use it as the polymer compound (a-2) having a reactive group.

Reacting any known compound with isocyanates with at least two isocyanate-reactive hydrogen atoms, for example with a functionality of 2 to 8 and a number average molar mass of 400 g/mol to 15000 g/mol. It is possible to use as polymeric compound (b) having a functional group: for example, it is possible to use compounds selected from the group consisting of polyether polyols, polyester polyols and mixtures thereof.

Polyetherols are, for example, catalyzed from epoxides, such as propylene oxide and/or ethylene oxide, or hydrogen-active starting compounds, such as aliphatic alcohols, phenyls, amines, carboxylic acids, water, or sucrose, sorbitol or Made from tetrahydrofuran with compounds based on natural substances such as mannitol. Here, the catalyst may consist of a basic catalyst and a double metal cyanide catalyst, for example as described in PCT/EP2005/010124, EP 90444 or WO 05/090440.

Polyesterols are obtained, for example, from aliphatic or aromatic dicarboxylic acids and polyhydric alcohols, polythioether polyols, polyesteramides, hydroxylated polyacetals and/or hydroxylated aliphatic polycarbonates, preferably in the presence of esterification catalysts. Manufactured. Other possible polyols are described, for example, in “Kunststoffhandbuch [Plastic Handbook], Volume 7, Polyurethane” [Polyurethane], Carl Hanser Verlag, 3rd Edition, 1993, Chapter 3.1.

In addition to the polyetherols and polyesterols mentioned above, other materials used are also called polyether polyetherols or polyesterols, which are filler-containing polyetherols or polyesterols. Preferably, these compounds comprise dispersed particles made of thermoplastics, for example consisting of olefinic monomers such as acrylonitrile, styrene, (meth)acrylate, (meth)acrylic acid and/or acrylamide. Polyols containing these fillers are known and commercially available. These production methods are described, for example, in DE 111 394, US 3 304 273, US 3 383 351, US 3 523 093, DE 1 152 536, DE 1 152 537 WO 2008/055592 and WO 2009/128279. ..

In a particularly preferred embodiment of the invention, component (b) comprises polyetherols, more preferably polyesterols.

The catalyst (c) significantly reacts with the polyol (b), the chain extender and the cross-linking agent (f), the chemical blowing agent (e) having an organic substance, and optionally the modified polyisocyanate (a). To accelerate. Here, catalyst (c) comprises an incorporable amine catalyst. These are groups which are reactive towards at least 1, preferably 1 to 8, particularly preferably 1 to 2, isocyanates, such as primary amine groups, secondary amine groups, hydroxy groups, amides or It has a urea group, preferably a primary amine group, a secondary amine group or a hydroxy group. Primarily, incorporable amine catalysts are used in the production of low emission polyurethanes used especially in the automotive interior sector. These catalysts are known and are described, for example, in EP 1888664. These preferably include compounds which, in addition to the isocyanate-reactive group, contain one or more tertiary amino groups. Preferably, at least one of the tertiary amino groups of the incorporable catalyst has at least two aliphatic hydrocarbon moieties (preferably having 1 to 10 carbon atoms per moiety, particularly preferably 1 With 1 to 6 carbon atoms per moiety). Particularly preferably, the tertiary amino group has two independent moieties selected from methyl and ethyl moieties and also other organic moieties. Examples of embeddable catalysts used are bisdimethylaminopropylurea, bis(N,N-dimethylaminoethoxyethyl)carbamate, dimethylaminopropylurea, N,N,N-trimethyl-N-hydroxyethylbis(amino Propyl ether), N,N,N-trimethyl-N-hydroxyethyl bis(aminoethyl ether), diethylethanolamine, bis(N,N-dimethyl-3-aminopropyl)amine, dimethylaminopropylamine, 3-dimethyl Aminopropyl-N,N-dimethylpropane-1,3-diamine, dimethyl-2-(2-aminoethoxyethanol), 1,3-bis(dimethylamino)propan-2-ol, N,N-bis(3 -Dimethylaminopropyl)-N-isopropanolamine, bis(dimethylaminopropyl)-2-hydroxyethylamine, N,N,N-trimethyl-N-(3-aminopropyl)bis(aminoethyl ether), 3-dimethylamino Isopropyl diisopropanolamine, and mixtures thereof.

It is also possible to make polyurethanes using conventional catalysts in addition to the amine catalysts that can be incorporated. The conventional catalysts include amidines such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary amines such as triethylamine, tributylamine, dimethylbenzylamine, N-methyl-, N-ethyl-. And N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylbutanediamine, N,N,N',N'-tetramethylhexanediamine, Pentamethyldiethylenetriamine, tetramethyldiaminoethylether, bis(dimethylaminopropyl)urea, dimethylpiperazine, 1,2-dimethylimidazole, 1-azabicyclo[3.3.0]octane, preferably 1,4-diazabicyclo[2. 2.2] is the octane. Also, organometallic compounds, preferably organotin compounds, such as tin(II) salts of organic carboxylic acids such as tin(II) acetate, octoate tin(II), ethylhexanetin(II) and tin(II) laurate. ), dialkyltin(IV) salts of organic carboxylic acids such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate, and bismuth carboxylates such as bismuth (III) neodecanoate, 2-ethylhexanebismuth. It is possible to use bismuth octoate and mixtures thereof. The organometallic compounds are used alone or preferably in combination with strongly basic amines. If component (b) comprises an ester, it is preferable to use only amine catalysts. In a particularly preferred embodiment, the catalyst (c) used comprises only incorporable catalysts.

If catalysts (c) are used, they are, for example, based on the weight of component (b), at a concentration of 0.001% to 5% by weight, in particular 0.05% to 2% by weight. Or, respectively, as a combination of catalysts.

Component (d) used is one or more CH-acidic compounds of the general formula R ¹ —CH ₂ —R ² . Here, the acidity of the CH ₂ group is generated by the ^two electron-withdrawing moieties R ¹ and R ² . The moieties R ¹ and R ² are each independently of the general formula —C(O)—R ³ or —CN, where moiety R ³ is —NH ₂ , —NH—R ⁴ , —NR ⁵ R. ⁶ , OR ⁷ or R ⁸ ), the compound of general formula R ¹ —CH ₂ —R ² is a CH—acidic compound. Here, the moieties R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are independently selected from the group consisting of optionally substituted aliphatic, araliphatic or aromatic hydrocarbons. Wherein, ^{R 1} and / or ^{R 2,} preferably in -CN or -C (O) -R ³ (wherein, ^{R 3} is ^{-NH-R 4,} in -NR ⁵ R 6, OR ⁷ or ^{R 8} there), more preferably -CN or -C (O) -R ³ (wherein, ^{R 3} is ^-NR 5 ^R 6, oR ⁷ or ^{R 8),} most preferably -CN, oR ⁷ or ^{R 8} Is. Preferably, the moieties R ¹ and R ² are -CN groups. The pKa of the component (d) of the present invention at 25°C in water is preferably 0.5 to 16, more preferably 8 to 14.0, and most preferably 8 to 13.5.

Preferably, in each case, the moieties R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ^{8 which} are independent of one another have 1 to 15, preferably 2 to 10 carbon atoms (having a substitution). May also be present). Preferably, in that case, the substituents are one or more of the isocyanate-reactive groups which advantageously contain an isocyanate-reactive hydrogen atom. Isocyanate-reactive groups of this type may be, for example, —OH, —NH— or —NH ₂ groups which preferably have carboxylic acid groups or carboxylic acid amide groups which are not considered to be isocyanate-reactive groups. Good. Particularly preferred isocyanate-reactive groups are one or more OH groups, particularly preferably one OH group. When R ³ is —NH ₂ or —NHR ⁴ , the —NH ₂ or —NHR ⁴ group is isocyanate-reactive except when the moiety R ⁴ is a moiety bearing an OH, —NH— or —NH ₂ group. Not considered to be the basis.

In another preferred embodiment, ^{R 3} _{is, -NH 2, -NH-CH 3} , -OCH 3, -N (CH 3) 2, -NH- (C 2 H 4) -OH or _-CH 2 -C (O) O-CH _{3, preferably -NH-CH 3, -OCH 3,} -N (CH 3) 2, -NH- (C 2 H 4) -OH or _-CH 2 -C (O) O- CH _3, more preferably -OCH _3, -N _{(CH 3) 2} or _{-CH 2 -C (O) O-} CH 3. Particularly preferred as the component (d) is dimethyl 1,3-acetonedicarboxylate, N-methylacetoacetamide, N,N-dimethylacetoacetamide, 2-cyanoacetoacetamide, methyl cyanoacetate, 2- Cyano-N-(2-hydroxyethyl)acetamide and methyl-2-(2-hydroxyethylcarbamoyl)ethanol, more particularly 2-cyano-N-(2-hydroxyethyl)acetamide and methyl-2-(2-hydroxyethyl). Carbamoyl) ethanol.

The molecular weight of the CH-acidic compound (d) is preferably above 250 g/mol, more preferably above 300 g/mol, and more particularly above 350 g/mol. This is especially the case when the CH-acidic compound (d) contains no isocyanate-reactive groups. These compounds preferably have more than one, more preferably 2 to 5, more especially 3 or 4 CH-acidic groups. Examples of such compounds are more particularly the reaction products of malonic acid and diols in a molecular ratio of 2:3, such as diethylene glycol or trimethylolpropane triacetoacetate, more particularly trimethylolpropane triacetoacetate.

The amount of component (d) used for the present invention is preferably 0.01% to 5% by weight, particularly preferably 0.05% by weight, based on the total weight of components (a) to (f). % To 2% by mass, particularly 0.1% to 1% by mass.

If the purpose is to select the polyurethane foam form of the invention, the reaction mixture according to the invention also comprises a blowing agent (e). Here, it is possible to use any blowing agent known for the production of polyurethanes. These blowing agents may include chemical and/or physical blowing agents. These foaming agents are described, for example, in Kunststoffhandbuch [Plastic Handbook], Volume 7, Polyurethane [Polyurethane]," Carl Hanser Verlag, 1993, 3rd Edition, Chapter 3.4.5. Here, the term chemical blowing agent means a compound which forms a gaseous product on reaction with an isocyanate. Examples of these blowing agents are water and carboxylic acids. The term physical blowing agent means a compound that is dissolved or emulsified in the starting material for the polyurethane manufacturing reaction and that evaporates under the conditions that form the polyurethane. Examples of these blowing agents are hydrocarbons, halogenated hydrocarbons, and other compounds such as perfluorinated alkanes such as perfluorohexane and chlorofluorocarbons, ethers, esters, ketones, acetals and/or liquid carbon dioxide. .. The blowing agent is preferably used in an amount such that the density of the resulting polyurethane foam is from 10 g/L to 850 g/L, preferably from 20 g/L to 800 g/L, especially from 25 g/L to 500 g/L. Particularly preferred is the use of a blowing agent containing water.

The chain extenders and crosslinkers (f) used here can be compounds with a molecular weight of less than 400 g/mol having groups reactive towards at least two isocyanates. Here, the term chain extender is used for molecules which have two of the hydrogen atoms reactive towards isocyanates. Here, the term crosslinker is used for molecules which have hydrogen atoms reactive towards more than two isocyanates. However, it is also possible here to eliminate the chain extenders or crosslinkers. However, the addition of chain extenders, cross-linking agents, or optionally mixtures thereof, may prove beneficial in altering mechanical properties (eg hardness).

If a chain extender and/or crosslinker (f) is used, the method of use may consist of the chain extender and/or crosslinker known in polyurethane manufacture. Preferably, these are low molecular weight compounds having functional groups reactive towards isocyanates, such as glycerol, trimethylolpropane, glycols and diamines. Other possible low molecular weight chain extenders and/or crosslinkers are, for example, Kunststoffhandbuch [Plastic Handbook], Volume 7, Polyurethane (Polyurethane),” Carl Hanser Verlag, 3rd Edition 1993, Chapter 3.2 and. It is described in Chapter 3.3.2.

Furthermore, it is possible to use auxiliaries and/or additives (g). Here, it is possible to use any auxiliaries and additives known for the production of polyurethanes. The above may consist, for example, of surface-active substances, foam stabilizers, cell regulators, release agents, fillers, dyes, pigments, flame retardants, hydrolysis stabilizers, fungistatic and bacteriostatic substances. .. These substances are known, for example Kunststoffhandbuch [Plastic Handbook], Vol. 7, Polyurethane [Polyurethane]", Carl Hanser Verlag, 1993 3rd edition, chapters 3.4.4 and 3.4.6. Chapters to Chapter 3.4.11.

Generally, the polyisocyanates (a), polyols (b), CH-acidic compounds (d) used in the production of the polyurethanes of the present invention, and, if used, blowing agents (e) and chain extenders. And/or the cross-linking agent (f) is composed of the NCO group of the polyisocyanate (a), the components (b), (c) and (d), and optionally the reactive hydrogen atom of (e) and (f). It is used in an amount such that the equivalent ratio to the total number is 0.75 to 1.5:1, preferably 0.80 to 1.25:1. Usually, when the foamed plastic contains at least a plurality of isocyanurate groups, the NCO groups of the polyisocyanate (a) and the components (b), (c), (d) and optionally (e) and (f) of The equivalent ratio to the total number of reactive hydrogen atoms is 1.5 to 20:1, preferably 1.5 to 8:1. Here, a ratio of 1:1 corresponds to an isocyanate index of 100.

The mass and qualitative differences between the individual starting materials (a) to (g) used for the production of the polyurethane of the invention in the form of thermoplastic polyurethane, flexible foam, semi-rigid foam, rigid foam or monolithic foam are small. : For example, the production of compressed polyurethane does not use blowing agents, preferably thermoplastic polyurethane strictly uses difunctional starting materials. Moreover, it is possible, for example, to modify the elasticity and hardness of the polyurethanes of the invention by the functionality and chain length of relatively high molecular weight compounds having at least two reactive hydrogen atoms. These modifications are known to those skilled in the art.

Starting materials for the production of compressed polyurethanes are described, for example, in EP 098146 or EP 1460094, starting materials for the production of flexible foams, for example in PCT/EP2005/010124 and EP 1529792, for the production of semi-rigid foams. Starting materials for are described, for example, in Kunststoffhandbuch [Plastic Handbook], Volume 7, Polyurethane [Polyurethane], Carl Hanser Verlag, 3rd Edition, 1993, Chapter 5.4, starting materials for the production of rigid foams. Materials are described in PCT/EP2005/010955, starting materials for the production of monolithic foams are described in EP 364854, US 5506275 or EP 897402. Therefore, in each case, the CH-acidic compound (d) is added to the starting materials described in said document.

The invention provides not only the method of the invention, but also the polyurethanes obtainable by the method of the invention. Preferably, the polyurethane of the present invention is used in enclosed spaces, for example in housings as insulation, such as insulation for pipes and refrigerators, in furniture production, for example as decorations or seat cushions, and for example in handles, dashboards, It is used in vehicle interiors as door cladding, carpet lining foam, sound absorbing foam, such as roof linings and headrests, or control buttons. Particular preference here is given to CH-acidic compounds having one or more isocyanate-reactive groups. They consist of combining the CH-acidic compound (d) with the polyurethane skeleton, first of all under the required conditions, for example at elevated temperatures or in the sun, compared to the absence of groups reactive towards isocyanates. It makes it possible to provide long-term effectiveness, in particular longer-term aldehyde reducibility. Secondly, the CH-acidic compounds (d) with incorporable groups provide polyurethanes which not only have a low emission of aldehydes, but roughly speaking also a low emission of volatile organic compounds.

The present invention will be described below with reference to examples.

Starting material:
Polyol A: a polyether-ol polyol based on ethylene oxide and propylene oxide having a propylene oxide content of 84% by weight and an ethylene oxide content of 14% by weight, with an OH number of 28 mg KOH/g and a functionality of 2.7. B: Polyether all TEOA based on polyol A (35%), propylene oxide (45%) and dimethylaminopropylamine (20%) with an OH number of 250 mg KOH/g and a functionality of 2.0: Triethanolamine Isopur SU-12021: Black paste from ISL-Chemie Jeffcat ZF10: Catalyst from Huntsman Jeffcat DPA: Catalyst from Huntsman

Additive:
A1: Dimethyl 1,3-acetone dicarboxylic acid A2: N-methylacetoacetamide A3: N,N-dimethylacetoacetamide A4: 2-Cyanoacetoacetamide A5: Methyl cyanoacetate A6: 2-Cyano- N-(2-hydroxyethyl)acetamide A7: Methyl-2-(2-hydroxyethylcarbamoyl)ethanoate A8: Reaction product of malonic acid and diethylene glycol (2:3-Mw 458)
A9: trimethylolpropane triacetoacetate (Mw 386)Z

A6 and A7 were added to the mixture A in the form of a 10% strength by weight aqueous solution.

Isocyanate A: A mixture of 85 parts by weight of carbodiimide-modified 4,4'-MDI and 15 parts by weight of polymeric diphenylmethane diisocyanate PMDI having an NCO content of 27.1.

Mixture A with the following ingredients:
92.0 parts by mass of Polyol A,
3.0 parts by mass of polyol B,
1.5 parts by mass of TEOA,
0.5 parts by mass of Isopur SA-21050,
1.9 parts by weight of water,
0.4 parts by mass of Jeffcat DPA,
0.2 parts by mass of Jeffcat ZF10,
0.5 parts by mass of the compounds A1 to A7 of Table 1,
Was prepared by mixing.

Mixture A, isocyanate component A and the additives of Table 1 were mixed together at an isocyanate index of 100 and placed in a closed mold to give a shaped article with an average density of 160 g/L.

Formaldehyde was measured by a procedure based on ASTM D5116-06. The size of the chamber was 4.7 liters. The polyurethane sample used was a part measuring 110 mm x 100 mm x 25 mm. When the molded foam was tested, the part consisting of the interior of the foam was used. The temperature of the test chamber during the test was 65° C. and the relative humidity was 50%. The air exchange rate was 3.0 liters per hour. The exhaust stream with volatile aldehydes from polyurethane was passed through a cartridge with silica coated with 2,4-dinitrophenylhydrazine for a period of 120 minutes. Then the DNPH cartridge was eluted with a mixture of acetonitrile and water. The concentration of formaldehyde in the eluate was measured by HPLC. The detection limit of formaldehyde emission of this setting is ≦11 μg/m ³ .

Table 1: Semi-rigid foam without additives (reference) measured in the chamber and semi-rigid added at the specified concentrations (parts by mass) relative to the total mass of the mixture A of additives A1 to A9. Formaldehyde value for foam.

Table 2: VOC values (ppm) according to VDA 278 of semi-rigid foams produced when the additives A4, A5, A6, A7 and A9 were added individually.

Claims (10)

A method for producing polyurethane, comprising:
(A) polyisocyanate,
(B) a polymer compound having a group reactive with isocyanate,
(C) A catalyst containing an embeddable amine catalyst, wherein the embeddable amine catalyst contains one or more tertiary amino groups in addition to an isocyanate-reactive group. A group wherein the group reactive with respect to is selected from the group consisting of primary amine groups, secondary amine groups, hydroxy groups, amide and urea groups,
(D) CH-acidic compound of the general formula R ¹ —CH ₂ —R ² (wherein R ¹ and R ² are, independently of each other, an electron of the general formula —C(O)—R ³ or —CN. an attracting portion, wherein, ^{R 3 _{is, -NH 2, -NH-R 4}} , is selected from the group consisting of -NR ⁵ R 6, oR ⁷ or ^{R 8, wherein,} R ^{4, R} 5, R ⁶ , R ⁷ or R ⁸ are independently selected from the group consisting of optionally substituted aliphatic, araliphatic or aromatic hydrocarbons), and optionally,
(E) a foaming agent,
(F) a chain extender and/or a crosslinking agent, and
(G) auxiliary agents and/or additives,
Are mixed to provide a reaction mixture, the reaction mixture is allowed to complete the reaction to provide a polyurethane, and the compound R ¹ —CH ₂ —R ² is selected from —OH, —NH— or —NH _2. One or more isocyanate-reactive groups (however, a carboxylic acid group or a carboxylic acid amide group is not regarded as an isocyanate-reactive group), or the molecular weight of the CH-acidic compound (d) exceeds 250 g/mol. A method characterized by. The group wherein the moieties R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are, in each case independently of one another, an aliphatic hydrocarbon having 1 to 15 carbon atoms which may be substituted. The method of claim 1 selected from: The method according to claim 1, wherein the CH-acidic compound (d) is trimethylolpropane triacetoacetate having a molecular weight of more than 250 g/mol. The method according to claim 1 or 2, wherein the content of the component (d) is 0.01% by mass to 5% by mass based on the total mass of the components (a) to (f). The method according to any one of claims 1 to 3, wherein the polymer compound (b) having a group reactive with isocyanate contains polyetherol. The process according to claim 1 or 2, wherein the compound used as the incorporable catalyst has one or more tertiary aliphatic amino groups in addition to the isocyanate-reactive group. 7. The method of claim 6, wherein the one or more tertiary aliphatic amino groups, independently of each other, has two moieties selected from methyl and ethyl moieties and also has another organic moiety. The method according to any one of claims 1 to 6, wherein the polyurethane is a polyurethane foam having an average density of 20 g/L to 850 g/L. 7. The method according to any one of claims 1 to 6, wherein the polyurethane is a compressed polyurethane having an average density of more than 850 g/L. The method of claim 9, wherein the polyurethane is a cable sheath.